Sunan an-Nasa'i 3478

It was narrated from Abu Hurairah that a man from Banu Fazarah came to the Messenger of Allah and said:"My wife has given birth to a black boy." The Messenger of Allah said: "Do you have camels?" He said: "Yes." He said: "What color are they?" He said: "Red." He said: "Are there any gray ones among them?" He said: "There are some gray ones among them." He said: "Where do you think they come from?" He said: "Perhaps it is hereditary." He said: "Likewise, perhaps this is hereditary